EP0263407B1 - Novel hollow fiber bushing and method of making hollow fibers - Google Patents
Novel hollow fiber bushing and method of making hollow fibers Download PDFInfo
- Publication number
- EP0263407B1 EP0263407B1 EP19870114185 EP87114185A EP0263407B1 EP 0263407 B1 EP0263407 B1 EP 0263407B1 EP 19870114185 EP19870114185 EP 19870114185 EP 87114185 A EP87114185 A EP 87114185A EP 0263407 B1 EP0263407 B1 EP 0263407B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- diameter
- bushing
- tube
- ratio
- tips
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000012510 hollow fiber Substances 0.000 title claims description 11
- 238000004519 manufacturing process Methods 0.000 title description 7
- 239000000835 fiber Substances 0.000 claims description 33
- 239000003365 glass fiber Substances 0.000 claims description 26
- 239000006060 molten glass Substances 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 16
- 239000011521 glass Substances 0.000 claims description 11
- 230000001105 regulatory effect Effects 0.000 claims 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 239000000463 material Substances 0.000 description 4
- 229910000629 Rh alloy Inorganic materials 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- PXXKQOPKNFECSZ-UHFFFAOYSA-N platinum rhodium Chemical compound [Rh].[Pt] PXXKQOPKNFECSZ-UHFFFAOYSA-N 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229910001260 Pt alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005524 ceramic coating Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 239000012783 reinforcing fiber Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/08—Bushings, e.g. construction, bushing reinforcement means; Spinnerettes; Nozzles; Nozzle plates
- C03B37/081—Indirect-melting bushings
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
- C03B37/022—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from molten glass in which the resultant product consists of different sorts of glass or is characterised by shape, e.g. hollow fibres, undulated fibres, fibres presenting a rough surface
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/08—Bushings, e.g. construction, bushing reinforcement means; Spinnerettes; Nozzles; Nozzle plates
- C03B37/083—Nozzles; Bushing nozzle plates
Definitions
- the present invention relates to the production of hollow glass fibers. More particularly, the present invention relates to apparatus and methods used in producing hollow fibers having more uniform ratios of internal to external diameters.
- Hollow glass fibers of the claimed strands typified in this patent are fibers having outside diameters of 0.00762 to 0.0762 mm (0.0003 to 0.003 inches) and having 10 to 65 percent of their volume hollow.
- the hollow glass fibers described in the aforementioned patent found use in filament wound application, such as a resin reinforcement for radar domes, and may also be used as a resin reinforcement for motor cases, storage tanks and the like.
- the advantage of hollow glass fibers was to provide a significant improvement in the strength to weight ratio of reinforcing fibers utilized to reinforce composites. Also provided, as stated in the aforementioned patent, was a significant reduction in the dielectric constant of materials reinforced with the hollow glass fibers of the patent over those reinforced with solid fibers.
- the hollow glass fibers produced in a multiple fiber strand had little or no uniformity with respect to the concentricity of the central lumen of the fibers.
- the K value of the fibers that is the ratio of the inside diameter of the central lumen of the fiber to the outside diameter of the hollow fiber was found to be very erratic and subject to wide variations in any given strand of fibers produced.
- Hollow glass fiber strands containing hollow filaments or fibers therein which possess more uniform ratios of inside to outside diameters and better concentricity of the central lumen are still a desired goal.
- the object of the invention is to provide an apparatus and a method for producing glass fibers having K values more uniform than those heretofore obtainable.
- an apparatus for producing hollow glass fibers comprising a source of molten glass, a bushing having a plurality of orifices therethrough for passage of molten glass streams from said source, a plurality of tubes extending into each orifice and said tubes restricting the orifices to form an annulus therein and having a central gas passageway therein throughout the length of the orifice and means for feeding gas to said tubes characterized by the tubes terminating in the same plane as the terminus of said orifices and the diameter of said passageway and the diameter of the orifice being such that they correspond to the ratio of the internal diameter to the external diameter desired in the fibers drawn from said apparatus and the means for feeding gas to said tubes being designed to feed the gas at a regulable or controlled pressure.
- This method of forming hollow glass fibers comprising feeding molten glass from a molten glass source through a plurality of fiber forming tips passing a gas stream through a tube positioned inside of and concentric with the walls of said tips to thereby cause molten glass to pass through an annulus around said tube, passing gas through the center of the molten glass as it exits the tip at a pressure sufficient to provide a hollow concentrical lumen
- an air column is established having a diameter in relation to the outside diameter of the annulus that is substantially the same as the ratio of internal to external diameter of the fibers formed in said glass cone as it solidifies in the atmosphere and choosing the diameter of the tube and the diameter of the tip to a value which provide the same ratio in said bushing tip, the tubes terminating in the same plane as the terminus of the fiber forming tips.
- the fibers made by the process are characterized in their new form by having a better concentricity in the central lumen than heretofore possible and more uniform K values than fibers heretofore produced. This results in a more uniform strength to weight ratio when these fibers are utilized in composites to provide strength to such materials as thermoset and thermoplastic resins.
- the novel apparatus described to produce the improved hollow fibers is durable, simple in construction and provides consistent fiber quality during the bushing life.
- the invention involves providing a hollow fiber forming bushing, wherein a gas is fed to molten glass emanating from the bushing, through a multiplicity of hollow tips depending from the bushing, each tip having a tube with a centrally defined gas passage therein, forming with the walls of said tips an annulus through said tips for glass to pass therethrough and means to pass gas through said tubes, characterized in that the tubes terminate in the same plane as the terminus of the hollow tips of the bushing and the diameter of the gas passage and the diameter of the annulus are chosen to provide a ratio corresponding to the ratio of internal diameter to external diameter in the hollow fiber produced by said bushing, generally in the range of 0.5 to 0.9, preferably between 0.6 and 0.8.
- a bushing indicated at 1 having a tip plate, faceplate or bottom member 13 (hereinafter called tip plate), in which are positioned as shown in Fig. 2 four bushing tips 7. While four tips are shown in Fig. 2 it will be of course understood by the skilled artisan more than the four tips shown can be employed, if desired. Thus, while the bushing in Fig. 2 contains four fiber forming tips it will be understood by the skilled artisan that the number of tips can be increased to any suitable number to provide the requisite number of filaments per strand desired for a given strand product.
- each air manifold 6 is shown feeding a single bushing tip through a single gas delivery tube 10 which in turn feeds a single bushing tip 7.
- the gas manifold 6 and its associated gas chamber 4 would feed multiple, aligned tubes 10 which would be located in and feed a multiplicity of tips 7.
- the gas delivery tube 10 is internally chamfered to an opening a 17 which is larger in diameter than the conduit 9 through which gas is introduced to opening 17.
- Conduit 9 and the tip 7 terminate in the same horizontal plane and discharge their contents to the atmosphere in that same horizontal plane.
- the arrangement of the outside wall of the concentric tube 10 and interior walls of the tip 7 provide an annulus 16, which surrounds the bottom section of the tube 10.
- the annulus 16 provides a passageway through which glass accumulating in the area 25 of the bushing tip is passed outside of the bushing proper to the atmosphere. As can be seen clearly in the drawing of Fig. 1, the glass emanating from the annulus 16 and the air leaving chamber 17 at 18 enter the atmosphere together.
- a bracket member 11 is provided around the external surface of the gas delivery tube 10. Holes 24 are provided in tip plate 13 and the side, pieces or tabs 14 of the bracket member 11 are inserted through the holes 24 in the faceplate 13. One of these tabs is shown inserted through the hole 24 on the right hand side of Fig. 1. The configuration shown on the left hand side of the same figure shows the finished version of this bracket member.
- the bracket 14 as shown on the right hand side of the drawing is inserted through the hole 24 in the bushing tip plate 13. After insertion a welding torch is applied to the surface of the tab 14 which is protruding below the tip plate 13 and it is heated to its melting point.
- the tab 14 is designed in mass so that when heat is applied and the metal melts, it forms the button 15 shown on the left hand side of Fig. 1 in the tip plate thereby becoming a part of that tip plate. In finished form, the right side of the orifice in Fig. 1 will look the same as the left side as shown.
- the arms 14 of the bracket 11 become an integral part of the tip plate 13 and the upper section of the bracket 11 is welded to the outside wall of the gas delivery tube 10 at weld 22. This arrangement coupled with the rigid attachment of tube 10 through wall 30 to gas conduit 6 provides a truss arrangement for the tip plate 13.
- the described truss arrangement is such that it provides a tip plate that has a substantially reduced tendency to sag thereby maintaining the tube 10 and tip 7 spatially constant with respect to each other during use.
- the tips 7 are welded to the faceplate 13 at welds 23 in a manner conventional to those skilled in the art.
- the bushing 1 itself is electrically heated as shown in Fig. 2. This heat is applied through a suitable bushing connector 3 which is connected to an electrical terminal 12.
- the terminal 12 is normally attached to the secondary of a power transformer not shown but this arrangement is well understood by those skilled in the art, and can be readily found in the book "The Manufacturing Technology of Continuous Glass Fibers", by K. L. Lowenstein, Elsevier Publishing Co., 1973, Chapter V.
- molten glass from a suitable glass source is passed into the bushing 1 and passes downwardly through the area 25 above each of the bushing tips 7 and out to the atmosphere through annulus 16 in each of the bushing tips 7.
- a gas stream preferably air, is passed through manifold 6 via conduit 4 through the central passageway 9 into an air delivery tube 10 associated with each of the bushing tips 7. This air is passed downwardly in passageway 9 of tube 10 to the flared opening 17, and exits the tips at the same horizontal planar level as the molten glass emanating from through annulus 16.
- a more stable attenuation process is therefore achieved and more uniform and concentric lumens are provided in the glass fibers because the diameter of the air stream and the glass stream at the tip at point 18 are in approximately the same proportion as the desired end product, a condition which is not found to be true in the above referred to prior art.
- the lumen of the fibers formed are centrally located and are constantly in the same position regardless of whether or not the bushing tip plate should distort.
- the firm connection between the bracket member 11, the bushing tip plate 13 and the tube 10 maintains their spatial relationship constant.
- the welds 22 between the tube 10 and the bracket member 11 and the solid connection or button 15 formed by the side arm tabs 14 of the brackets 11 in the holes 24 provided in the faceplate for the tabs 14 and the welded attachment of conduit 6 to tube 10 at the other end provide a rigid, secure, truss-type attachment which substantially supports the tip plate 13 during use to help prevent any substantial distortion of the tip plate, thus keeping the tube 10 and the tip 7 in their constructed spatial relationship during operation.
- the bushing 1 of the figures shown may be constructed of any suitable bushing material utilized by the current state of the art.
- the bushings utilized in the instant application are constructed of precious metals, primarily platinum and platinum-rhodium alloy.
- An 80% platinum 20% rhodium alloy by weight is the preferred bushing material and is utilized not only for the bushing but for all other associated equipment such as the air distribution tubes, manifolds and so forth. Any surface in contact with the molten glass is thus in general a platinum rhodium alloy or its equivalent.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Inorganic Fibers (AREA)
Description
- The present invention relates to the production of hollow glass fibers. More particularly, the present invention relates to apparatus and methods used in producing hollow fibers having more uniform ratios of internal to external diameters.
- In US-A 3 510 393, from which the pre-characterising parts of
claims - In US-A 3 268 313 apparatus suitable for use in manufacturing the hollow glass fibers in the aforementioned patent is shown. Similarly, in US-A 3 421 873 alternative apparatus and methods are described where fibers can be produced which have intermittent hollowness along their length.
- While the aforementioned apparatus, methods and fibers have found some utility in the market place, their use has been limited due to several factors. One factor was the high cost of preparing the hollow glass fibers. This cost was high due to the fact that the apparatus was difficult to operate on a continuous basis without many process interruptions occurring during the formation of the fibers. The manufacturing costs consequently required high selling prices which was a deterrent in the marketplace. Further, the fibers produced by the processes and apparatus described in these patents, while hollow when initially produced from commercial size bushings, after a period of time produced were found to contain a significant large number of solid fibers as well as hollow glass fibers. Still further, the hollow glass fibers produced in a multiple fiber strand had little or no uniformity with respect to the concentricity of the central lumen of the fibers. Stated another way, the K value of the fibers, that is the ratio of the inside diameter of the central lumen of the fiber to the outside diameter of the hollow fiber was found to be very erratic and subject to wide variations in any given strand of fibers produced.
- Thus, despite the advent of the processes in the prior art to manufacture hollow glass fibers, the need still exists for processes and apparatus for producing hollow glass fibers of more uniform configuration and quality. Hollow glass fiber strands containing hollow filaments or fibers therein which possess more uniform ratios of inside to outside diameters and better concentricity of the central lumen are still a desired goal.
- The object of the invention is to provide an apparatus and a method for producing glass fibers having K values more uniform than those heretofore obtainable.
- This object is attained by an apparatus for producing hollow glass fibers comprising a source of molten glass, a bushing having a plurality of orifices therethrough for passage of molten glass streams from said source, a plurality of tubes extending into each orifice and said tubes restricting the orifices to form an annulus therein and having a central gas passageway therein throughout the length of the orifice and means for feeding gas to said tubes characterized by the tubes terminating in the same plane as the terminus of said orifices and the diameter of said passageway and the diameter of the orifice being such that they correspond to the ratio of the internal diameter to the external diameter desired in the fibers drawn from said apparatus and the means for feeding gas to said tubes being designed to feed the gas at a regulable or controlled pressure.
- In accordance with this invention also a process for producing improved hollow glass fibers is provided.
- This method of forming hollow glass fibers comprising feeding molten glass from a molten glass source through a plurality of fiber forming tips passing a gas stream through a tube positioned inside of and concentric with the walls of said tips to thereby cause molten glass to pass through an annulus around said tube, passing gas through the center of the molten glass as it exits the tip at a pressure sufficient to provide a hollow concentrical lumen is characterized in that an air column is established having a diameter in relation to the outside diameter of the annulus that is substantially the same as the ratio of internal to external diameter of the fibers formed in said glass cone as it solidifies in the atmosphere and choosing the diameter of the tube and the diameter of the tip to a value which provide the same ratio in said bushing tip, the tubes terminating in the same plane as the terminus of the fiber forming tips.
- The fibers made by the process are characterized in their new form by having a better concentricity in the central lumen than heretofore possible and more uniform K values than fibers heretofore produced. This results in a more uniform strength to weight ratio when these fibers are utilized in composites to provide strength to such materials as thermoset and thermoplastic resins. The novel apparatus described to produce the improved hollow fibers is durable, simple in construction and provides consistent fiber quality during the bushing life.
- In another aspect, the invention involves providing a hollow fiber forming bushing, wherein a gas is fed to molten glass emanating from the bushing, through a multiplicity of hollow tips depending from the bushing, each tip having a tube with a centrally defined gas passage therein, forming with the walls of said tips an annulus through said tips for glass to pass therethrough and means to pass gas through said tubes, characterized in that the tubes terminate in the same plane as the terminus of the hollow tips of the bushing and the diameter of the gas passage and the diameter of the annulus are chosen to provide a ratio corresponding to the ratio of internal diameter to external diameter in the hollow fiber produced by said bushing, generally in the range of 0.5 to 0.9, preferably between 0.6 and 0.8.
- For a more complete understanding of the present invention, reference is made to the accompanying drawing in which;
- Fig. 1 is a side elevation of a bushing suitable for producing improved hollow glass fibers, and;
- Fig. 2 is a front elevation of a bushing constructed in accordance with the instant invention to provide improved hollow glass fibers.
- In the accompanying drawing looking at Figs. 1 and 2 there is shown a bushing indicated at 1, having a tip plate, faceplate or bottom member 13 (hereinafter called tip plate), in which are positioned as shown in Fig. 2 four bushing tips 7. While four tips are shown in Fig. 2 it will be of course understood by the skilled artisan more than the four tips shown can be employed, if desired. Thus, while the bushing in Fig. 2 contains four fiber forming tips it will be understood by the skilled artisan that the number of tips can be increased to any suitable number to provide the requisite number of filaments per strand desired for a given strand product. Positioned concentric with the inside walls of the bushing tip 7 and located centrally therein is an
gas delivery tube 10 having acentral channel 9 communicating with anair passageway 4 in an air manifold member 6. Again as shown in the drawing of Fig. 2, each air manifold 6 is shown feeding a single bushing tip through a singlegas delivery tube 10 which in turn feeds a single bushing tip 7. In practice in a large bushing, where multiple bushing tips are typically arranged in rows, the gas manifold 6 and its associatedgas chamber 4 would feed multiple, alignedtubes 10 which would be located in and feed a multiplicity of tips 7. - At the base, the
gas delivery tube 10 is internally chamfered to an opening a 17 which is larger in diameter than theconduit 9 through which gas is introduced to opening 17.Conduit 9 and the tip 7 terminate in the same horizontal plane and discharge their contents to the atmosphere in that same horizontal plane. The arrangement of the outside wall of theconcentric tube 10 and interior walls of the tip 7 provide anannulus 16, which surrounds the bottom section of thetube 10. Theannulus 16 provides a passageway through which glass accumulating in thearea 25 of the bushing tip is passed outside of the bushing proper to the atmosphere. As can be seen clearly in the drawing of Fig. 1, the glass emanating from theannulus 16 and the air leaving chamber 17 at 18 enter the atmosphere together. An important consideration in providing thegas tube 10 with the expanded bottom section for the introduction of air is to establish an air column having a diameter in relation to the outside diameter of the annulus that is substantially the same as the ratio of internal to external diameter desired in the final hollow product. Thus, providing this desired ratio within the bushing tip it is found that theglass cone 8 in its final solidified filament form possesses a ratio of lumen diameter to external fiber diameter approximately the same as the ratio of the internal diameter ofgas conduit 9 atpoint 18 to the internal diameter of tip 7. By machining the tip 7 andtube 10 such that the diameter of opening 18 inconduit 9 and the internal diameter of tip 7 are correlated to provide a ratio of internal lumen to external fiber diameter that is desired in the final product, hollow glass fibers of that approximate desired ratio will be readily obtained. - In the preferred construction of the bushing in accordance with the instant invention a bracket member 11 is provided around the external surface of the
gas delivery tube 10.Holes 24 are provided intip plate 13 and the side, pieces ortabs 14 of the bracket member 11 are inserted through theholes 24 in thefaceplate 13. One of these tabs is shown inserted through thehole 24 on the right hand side of Fig. 1. The configuration shown on the left hand side of the same figure shows the finished version of this bracket member. Thus, thebracket 14 as shown on the right hand side of the drawing is inserted through thehole 24 in thebushing tip plate 13. After insertion a welding torch is applied to the surface of thetab 14 which is protruding below thetip plate 13 and it is heated to its melting point. Thetab 14 is designed in mass so that when heat is applied and the metal melts, it forms thebutton 15 shown on the left hand side of Fig. 1 in the tip plate thereby becoming a part of that tip plate. In finished form, the right side of the orifice in Fig. 1 will look the same as the left side as shown. Thearms 14 of the bracket 11 become an integral part of thetip plate 13 and the upper section of the bracket 11 is welded to the outside wall of thegas delivery tube 10 atweld 22. This arrangement coupled with the rigid attachment oftube 10 throughwall 30 to gas conduit 6 provides a truss arrangement for thetip plate 13. Since the bracket ends are now an integral part of thefaceplate 13, movement of thefaceplate 13 due to any slight warpage over time during use will be minimized and will cause thedelivery tube 10 to move in any direction that the tip 7 moves as a result of such warpage. Furthermore, the described truss arrangement is such that it provides a tip plate that has a substantially reduced tendency to sag thereby maintaining thetube 10 and tip 7 spatially constant with respect to each other during use. The tips 7 are welded to thefaceplate 13 atwelds 23 in a manner conventional to those skilled in the art. Thebushing 1 itself is electrically heated as shown in Fig. 2. This heat is applied through a suitable bushing connector 3 which is connected to anelectrical terminal 12. Theterminal 12 is normally attached to the secondary of a power transformer not shown but this arrangement is well understood by those skilled in the art, and can be readily found in the book "The Manufacturing Technology of Continuous Glass Fibers", by K. L. Lowenstein, Elsevier Publishing Co., 1973, Chapter V. - In conducting the process of the instant invention, molten glass from a suitable glass source is passed into the
bushing 1 and passes downwardly through thearea 25 above each of the bushing tips 7 and out to the atmosphere throughannulus 16 in each of the bushing tips 7. A gas stream, preferably air, is passed through manifold 6 viaconduit 4 through thecentral passageway 9 into anair delivery tube 10 associated with each of the bushing tips 7. This air is passed downwardly inpassageway 9 oftube 10 to the flared opening 17, and exits the tips at the same horizontal planar level as the molten glass emanating from throughannulus 16. By flaring the opening of thepassageway 9 at point 17 in the manner shown in the drawing the air stream exiting the end of tip 7 at 18 is larger in diameter than heretofore used in the aforementioned prior art patents. This provision of a larger diameter for the gas avoids the characteristic bulging of the cone of molten glass as shown by the prior art exemplified by US-A 3 268 313. Further, less air pressure is required to form the fiber lumen in the glass cone used to form the fibers with this arrangement. A more stable attenuation process is therefore achieved and more uniform and concentric lumens are provided in the glass fibers because the diameter of the air stream and the glass stream at the tip atpoint 18 are in approximately the same proportion as the desired end product, a condition which is not found to be true in the above referred to prior art. The lumen of the fibers formed are centrally located and are constantly in the same position regardless of whether or not the bushing tip plate should distort. The firm connection between the bracket member 11, thebushing tip plate 13 and thetube 10 maintains their spatial relationship constant. Thewelds 22 between thetube 10 and the bracket member 11 and the solid connection orbutton 15 formed by theside arm tabs 14 of the brackets 11 in theholes 24 provided in the faceplate for thetabs 14 and the welded attachment of conduit 6 totube 10 at the other end provide a rigid, secure, truss-type attachment which substantially supports thetip plate 13 during use to help prevent any substantial distortion of the tip plate, thus keeping thetube 10 and the tip 7 in their constructed spatial relationship during operation. - The
bushing 1 of the figures shown may be constructed of any suitable bushing material utilized by the current state of the art. Typically the bushings utilized in the instant application are constructed of precious metals, primarily platinum and platinum-rhodium alloy. An 80% platinum 20% rhodium alloy by weight is the preferred bushing material and is utilized not only for the bushing but for all other associated equipment such as the air distribution tubes, manifolds and so forth. Any surface in contact with the molten glass is thus in general a platinum rhodium alloy or its equivalent. Recourse to the utilization of zirconia stabilized or other grain stabilized platinum or platinum alloys may also be had as well as recourse to ceramic coatings on the bushing and exterior supports where glass fiber compositions requiring heat in the bushing above 1260°C (2300°F)are required. - Satisfactory hollow fibers may be produced utilizing the bushing and method herein described. In general, any glass composition which can be formed into a glass fiber will satisfactorily produce hollow fibers in accordance with the novel apparatus of the instant invention.
Claims (11)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US91441586A | 1986-10-02 | 1986-10-02 | |
US914415 | 1997-08-19 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0263407A1 EP0263407A1 (en) | 1988-04-13 |
EP0263407B1 true EP0263407B1 (en) | 1990-11-22 |
Family
ID=25434333
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19870114185 Expired EP0263407B1 (en) | 1986-10-02 | 1987-09-29 | Novel hollow fiber bushing and method of making hollow fibers |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0263407B1 (en) |
JP (1) | JPH0623072B2 (en) |
CA (1) | CA1294440C (en) |
DE (1) | DE3766340D1 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4735642A (en) * | 1985-10-20 | 1988-04-05 | Ppg Industries, Inc. | Hollow glass fiber bushing assembly |
US4758259A (en) * | 1986-10-02 | 1988-07-19 | Ppg Industries, Inc. | Hollow glass fiber bushing, method of making hollow fibers and the hollow glass fibers made by that method |
JP4975327B2 (en) * | 2006-01-25 | 2012-07-11 | 株式会社Espinex | Die and method for producing nanofiber using the same |
JP6507914B2 (en) * | 2015-07-31 | 2019-05-08 | 日本電気硝子株式会社 | Method of manufacturing glass fiber |
CN112981563B (en) * | 2021-02-03 | 2022-05-13 | 北京航空航天大学 | Hollow basalt fiber manufacturing device and manufacturing method |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE526900C (en) * | 1928-03-25 | 1932-04-04 | Walter Roessler | Method of spinning threads from glass |
US3510393A (en) * | 1962-10-01 | 1970-05-05 | Ppg Industries Inc | Hollow glass article |
-
1987
- 1987-08-12 CA CA000544338A patent/CA1294440C/en not_active Expired - Lifetime
- 1987-08-31 JP JP62219006A patent/JPH0623072B2/en not_active Expired - Lifetime
- 1987-09-29 DE DE8787114185T patent/DE3766340D1/en not_active Expired - Lifetime
- 1987-09-29 EP EP19870114185 patent/EP0263407B1/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE3766340D1 (en) | 1991-01-03 |
CA1294440C (en) | 1992-01-21 |
JPH0623072B2 (en) | 1994-03-30 |
JPS6389433A (en) | 1988-04-20 |
EP0263407A1 (en) | 1988-04-13 |
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